NGC 7213 - A key to the nature of liners?

view Abstract Citations (259) References (67) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS NGC 7213 : a key to the nature of liners ? Filippenko, A. V. ; Halpern, J. P. Abstract New optical spectra show that the nucleus of the S0 galaxy NGC 7213 resembles those of type 1 Seyferts: emission lines such as [Ne V] λ3426, He II λ4686, and broad Hα are visible, and a nonstellar component accounts for a substantial portion of the continuum at blue and ultraviolet wavelengths. Many of the emission-line intensity ratios suggest heating due to shocks, since they are similar to those in "Liners". After subtracting the stellar continuum careful measurements of various emission lines are presented and a number of important physical parameters are derived. The Seyfert characteristics of NGC 7213 are reviewed, and its shock features are reconciled with photoionization models. The arguments may apply to classical Liners as well. Finally, theoretical models are explored that can help explain the relationships discovered among the emission lines. Publication: The Astrophysical Journal Pub Date: October 1984 DOI: 10.1086/162521 Bibcode: 1984ApJ...285..458F Keywords: Emission Spectra; Galactic Nuclei; Interstellar Gas; Optical Emission Spectroscopy; Seyfert Galaxies; Spectrophotometry; Balmer Series; Hydrogen Clouds; Ionized Gases; Photoionization; Shock Heating; Spectral Line Width; Spectrum Analysis; Astrophysics full text sources ADS | data products SIMBAD (2) NED (2)